/*
 * Copyright 2002-2015 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package cn.tang.tframe.common.utils.lang;

import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Properties;

/**
 * Miscellaneous collection utility methods.
 * Mainly for internal use within the framework.
 *
 * @author Juergen Hoeller
 * @author Rob Harrop
 * @author Arjen Poutsma
 * @since 1.1.3
 */
public abstract class CollectionUtils {

	/**
	 * Return {@code true} if the supplied Collection is {@code null} or empty.
	 * Otherwise, return {@code false}.
	 * @param collection the Collection to check
	 * @return whether the given Collection is empty
	 */
	public static boolean isEmpty(Collection<?> collection) {
		return (collection == null || collection.isEmpty());
	}
	public static boolean isNotEmpty(Collection c) {
		return !isEmpty(c);
	}
	/**
	 * Return {@code true} if the supplied Map is {@code null} or empty.
	 * Otherwise, return {@code false}.
	 * @param map the Map to check
	 * @return whether the given Map is empty
	 */
	public static boolean isEmpty(Map<?, ?> map) {
		return (map == null || map.isEmpty());
	}

	/**
	 * Convert the supplied array into a List. A primitive array gets converted
	 * into a List of the appropriate wrapper type.
	 * <p><b>NOTE:</b> Generally prefer the standard {@link Arrays#asList} method.
	 * This {@code arrayToList} method is just meant to deal with an incoming Object
	 * value that might be an {@code Object[]} or a primitive array at runtime.
	 * <p>A {@code null} source value will be converted to an empty List.
	 * @param source the (potentially primitive) array
	 * @return the converted List result
	 * @see ObjectUtils#toObjectArray(Object)
	 * @see Arrays#asList(Object[])
	 */
	@SuppressWarnings("rawtypes")
	public static List arrayToList(Object source) {
		return Arrays.asList(ObjectUtils.toObjectArray(source));
	}

	/**
	 * Merge the given array into the given Collection.
	 * @param array the array to merge (may be {@code null})
	 * @param collection the target Collection to merge the array into
	 */
	@SuppressWarnings("unchecked")
	public static <E> void mergeArrayIntoCollection(Object array, Collection<E> collection) {
		if (collection == null) {
			throw new IllegalArgumentException("Collection must not be null");
		}
		Object[] arr = ObjectUtils.toObjectArray(array);
		for (Object elem : arr) {
			collection.add((E) elem);
		}
	}

	/**
	 * Merge the given Properties instance into the given Map,
	 * copying all properties (key-value pairs) over.
	 * <p>Uses {@code Properties.propertyNames()} to even catch
	 * default properties linked into the original Properties instance.
	 * @param props the Properties instance to merge (may be {@code null})
	 * @param map the target Map to merge the properties into
	 */
	@SuppressWarnings("unchecked")
	public static <K, V> void mergePropertiesIntoMap(Properties props, Map<K, V> map) {
		if (map == null) {
			throw new IllegalArgumentException("Map must not be null");
		}
		if (props != null) {
			for (Enumeration<?> en = props.propertyNames(); en.hasMoreElements();) {
				String key = (String) en.nextElement();
				Object value = props.getProperty(key);
				if (value == null) {
					// Potentially a non-String value...
					value = props.get(key);
				}
				map.put((K) key, (V) value);
			}
		}
	}


	/**
	 * Check whether the given Iterator contains the given element.
	 * @param iterator the Iterator to check
	 * @param element the element to look for
	 * @return {@code true} if found, {@code false} else
	 */
	public static boolean contains(Iterator<?> iterator, Object element) {
		if (iterator != null) {
			while (iterator.hasNext()) {
				Object candidate = iterator.next();
				if (ObjectUtils.nullSafeEquals(candidate, element)) {
					return true;
				}
			}
		}
		return false;
	}

	/**
	 * Check whether the given Enumeration contains the given element.
	 * @param enumeration the Enumeration to check
	 * @param element the element to look for
	 * @return {@code true} if found, {@code false} else
	 */
	public static boolean contains(Enumeration<?> enumeration, Object element) {
		if (enumeration != null) {
			while (enumeration.hasMoreElements()) {
				Object candidate = enumeration.nextElement();
				if (ObjectUtils.nullSafeEquals(candidate, element)) {
					return true;
				}
			}
		}
		return false;
	}

	/**
	 * Check whether the given Collection contains the given element instance.
	 * <p>Enforces the given instance to be present, rather than returning
	 * {@code true} for an equal element as well.
	 * @param collection the Collection to check
	 * @param element the element to look for
	 * @return {@code true} if found, {@code false} else
	 */
	public static boolean containsInstance(Collection<?> collection, Object element) {
		if (collection != null) {
			for (Object candidate : collection) {
				if (candidate == element) {
					return true;
				}
			}
		}
		return false;
	}

	/**
	 * Return {@code true} if any element in '{@code candidates}' is
	 * contained in '{@code source}'; otherwise returns {@code false}.
	 * @param source the source Collection
	 * @param candidates the candidates to search for
	 * @return whether any of the candidates has been found
	 */
	public static boolean containsAny(Collection<?> source, Collection<?> candidates) {
		if (isEmpty(source) || isEmpty(candidates)) {
			return false;
		}
		for (Object candidate : candidates) {
			if (source.contains(candidate)) {
				return true;
			}
		}
		return false;
	}

	/**
	 * Return the first element in '{@code candidates}' that is contained in
	 * '{@code source}'. If no element in '{@code candidates}' is present in
	 * '{@code source}' returns {@code null}. Iteration order is
	 * {@link Collection} implementation specific.
	 * @param source the source Collection
	 * @param candidates the candidates to search for
	 * @return the first present object, or {@code null} if not found
	 */
	@SuppressWarnings("unchecked")
	public static <E> E findFirstMatch(Collection<?> source, Collection<E> candidates) {
		if (isEmpty(source) || isEmpty(candidates)) {
			return null;
		}
		for (Object candidate : candidates) {
			if (source.contains(candidate)) {
				return (E) candidate;
			}
		}
		return null;
	}

	/**
	 * Find a single value of the given type in the given Collection.
	 * @param collection the Collection to search
	 * @param type the type to look for
	 * @return a value of the given type found if there is a clear match,
	 * or {@code null} if none or more than one such value found
	 */
	@SuppressWarnings("unchecked")
	public static <T> T findValueOfType(Collection<?> collection, Class<T> type) {
		if (isEmpty(collection)) {
			return null;
		}
		T value = null;
		for (Object element : collection) {
			if (type == null || type.isInstance(element)) {
				if (value != null) {
					// More than one value found... no clear single value.
					return null;
				}
				value = (T) element;
			}
		}
		return value;
	}

	/**
	 * Find a single value of one of the given types in the given Collection:
	 * searching the Collection for a value of the first type, then
	 * searching for a value of the second type, etc.
	 * @param collection the collection to search
	 * @param types the types to look for, in prioritized order
	 * @return a value of one of the given types found if there is a clear match,
	 * or {@code null} if none or more than one such value found
	 */
	public static Object findValueOfType(Collection<?> collection, Class<?>[] types) {
		if (isEmpty(collection) || ObjectUtils.isEmpty(types)) {
			return null;
		}
		for (Class<?> type : types) {
			Object value = findValueOfType(collection, type);
			if (value != null) {
				return value;
			}
		}
		return null;
	}

	/**
	 * Determine whether the given Collection only contains a single unique object.
	 * @param collection the Collection to check
	 * @return {@code true} if the collection contains a single reference or
	 * multiple references to the same instance, {@code false} else
	 */
	public static boolean hasUniqueObject(Collection<?> collection) {
		if (isEmpty(collection)) {
			return false;
		}
		boolean hasCandidate = false;
		Object candidate = null;
		for (Object elem : collection) {
			if (!hasCandidate) {
				hasCandidate = true;
				candidate = elem;
			}
			else if (candidate != elem) {
				return false;
			}
		}
		return true;
	}

	/**
	 * Find the common element type of the given Collection, if any.
	 * @param collection the Collection to check
	 * @return the common element type, or {@code null} if no clear
	 * common type has been found (or the collection was empty)
	 */
	public static Class<?> findCommonElementType(Collection<?> collection) {
		if (isEmpty(collection)) {
			return null;
		}
		Class<?> candidate = null;
		for (Object val : collection) {
			if (val != null) {
				if (candidate == null) {
					candidate = val.getClass();
				}
				else if (candidate != val.getClass()) {
					return null;
				}
			}
		}
		return candidate;
	}

	/**
	 * Marshal the elements from the given enumeration into an array of the given type.
	 * Enumeration elements must be assignable to the type of the given array. The array
	 * returned will be a different instance than the array given.
	 */
	public static <A, E extends A> A[] toArray(Enumeration<E> enumeration, A[] array) {
		ArrayList<A> elements = new ArrayList<A>();
		while (enumeration.hasMoreElements()) {
			elements.add(enumeration.nextElement());
		}
		return elements.toArray(array);
	}

	/**
	 * Adapt an enumeration to an iterator.
	 * @param enumeration the enumeration
	 * @return the iterator
	 */
	public static <E> Iterator<E> toIterator(Enumeration<E> enumeration) {
		return new EnumerationIterator<E>(enumeration);
	}


	/**
	 * Iterator wrapping an Enumeration.
	 */
	private static class EnumerationIterator<E> implements Iterator<E> {

		private final Enumeration<E> enumeration;

		public EnumerationIterator(Enumeration<E> enumeration) {
			this.enumeration = enumeration;
		}

		@Override
		public boolean hasNext() {
			return this.enumeration.hasMoreElements();
		}

		@Override
		public E next() {
			return this.enumeration.nextElement();
		}

		@Override
		public void remove() throws UnsupportedOperationException {
			throw new UnsupportedOperationException("Not supported");
		}
	}

	public static Map<String, String> valueToStringExcludeNull(Map<String, Object> map) {
		if (isEmpty(map)) {
			return Collections.emptyMap();
		}
		Map<String, String> reMap = new HashMap<>();
		for (Map.Entry<String, Object> entry : map.entrySet()) {
			if (StringUtils.isBlank(entry.getKey()) || null == entry.getValue()
					|| StringUtils.isBlank(entry.getValue().toString())) {
				continue;
			}
			String value = entry.getValue().toString();
			if (StringUtils.isBlank(value)) {
				continue;
			}
			reMap.put(entry.getKey(), value);
		}
		return reMap;
	}
	public static <E> void visitIterator(Iterator<E> dataList,BeanVisitor<E> visitor){
		if(null != dataList){
			while(dataList.hasNext()){
				E next = dataList.next();
				if(null != next){
					visitor.visit(next);
				}
			}
		}
	}
	public static <E> void visitIterator(Collection<E> dataList,BeanVisitor<E> visitor){
		if(null != dataList){
			visitIterator(dataList.iterator(),visitor);
		}
	}
	public static <E,F> List<F> convertIterator(Iterator<E> dataList,
	                                                 final BeanToOtherConvertor<E,F> convertor) {
		final List<F> results = new ArrayList<>();
		visitIterator(dataList, new BeanVisitor<E>() {
			@Override
			public void visit(E bean) {
				F f = convertor.convertBeanToOther(bean);
				if (null != f) {
					results.add(f);
				}
			}
		});
		return results;
	}
	public static <E,F> List<F> convertListOtherBean(List<E> dataList,
	                                                 final BeanToOtherConvertor<E,F> convertor) {
		final List<F> results = new ArrayList<>();
		visitIterator(dataList, new BeanVisitor<E>() {
			@Override
			public void visit(E bean) {
				F f = convertor.convertBeanToOther(bean);
				if (null != f) {
					results.add(f);
				}
			}
		});

		return results;
	}
	public static <E,F> F convertOtherBean(E e,
	                                       BeanToOtherConvertor<E,F> convertor) {
		if (null != e && null != convertor) {
			F f = convertor.convertBeanToOther(e);
			if (null != f) {
				return f;
			}
		}
		return null;
	}
	public interface BeanVisitor<E> {
		void visit(E bean);
	}
	public interface BeanToOtherConvertor<E,F> {
		F convertBeanToOther(E bean);
	}
	/**
	 * Adds all elements in the iteration to the given collection.
	 *
	 * @param collection  the collection to add to, must not be null
	 * @param iterator  the iterator of elements to add, must not be null
	 * @throws NullPointerException if the collection or iterator is null
	 */
	public static void addAll(Collection collection, Iterator iterator) {
		while (iterator.hasNext()) {
			collection.add(iterator.next());
		}
	}

	/**
	 * Adds all elements in the enumeration to the given collection.
	 *
	 * @param collection  the collection to add to, must not be null
	 * @param enumeration  the enumeration of elements to add, must not be null
	 * @throws NullPointerException if the collection or enumeration is null
	 */
	public static void addAll(Collection collection, Enumeration enumeration) {
		while (enumeration.hasMoreElements()) {
			collection.add(enumeration.nextElement());
		}
	}

	/**
	 * Adds all elements in the array to the given collection.
	 *
	 * @param collection  the collection to add to, must not be null
	 * @param elements  the array of elements to add, must not be null
	 * @throws NullPointerException if the collection or array is null
	 */
	public static void addAll(Collection collection, Object[] elements) {
		for (int i = 0, size = elements.length; i < size; i++) {
			collection.add(elements[i]);
		}
	}
	/**
	 * Reverses the order of the given array.
	 *
	 * @param array  the array to reverse
	 */
	public static void reverseArray(final Object[] array) {
		int i = 0;
		int j = array.length - 1;
		Object tmp;

		while (j > i) {
			tmp = array[j];
			array[j] = array[i];
			array[i] = tmp;
			j--;
			i++;
		}
	}
	/**
	 * Reverses the order of the given array.
	 *
	 * @param array  the array to reverse
	 */
	public static void toArray(final Object[] array) {
		int i = 0;
		int j = array.length - 1;
		Object tmp;

		while (j > i) {
			tmp = array[j];
			array[j] = array[i];
			array[i] = tmp;
			j--;
			i++;
		}
	}
	/**
	 * Gets the size of the collection/iterator specified.
	 * <p>
	 * This method can handles objects as follows
	 * <ul>
	 * <li>Collection - the collection size
	 * <li>Map - the map size
	 * <li>Array - the array size
	 * <li>Iterator - the number of elements remaining in the iterator
	 * <li>Enumeration - the number of elements remaining in the enumeration
	 * </ul>
	 *
	 * @param object  the object to get the size of
	 * @return the size of the specified collection
	 * @throws IllegalArgumentException thrown if object is not recognised or null
	 * @since Commons Collections 3.1
	 */
	public static int size(Object object) {
		int total = 0;
		if (object instanceof Map) {
			total = ((Map) object).size();
		} else if (object instanceof Collection) {
			total = ((Collection) object).size();
		} else if (object instanceof Object[]) {
			total = ((Object[]) object).length;
		} else if (object instanceof Iterator) {
			Iterator it = (Iterator) object;
			while (it.hasNext()) {
				total++;
				it.next();
			}
		} else if (object instanceof Enumeration) {
			Enumeration it = (Enumeration) object;
			while (it.hasMoreElements()) {
				total++;
				it.nextElement();
			}
		} else if (object == null) {
			throw new IllegalArgumentException("Unsupported object type: null");
		} else {
			try {
				total = Array.getLength(object);
			} catch (IllegalArgumentException ex) {
				throw new IllegalArgumentException("Unsupported object type: " + object.getClass().getName());
			}
		}
		return total;
	}

}
